6) Pretty much no one watches cable news.I have little to add to this one...I guess there are a couple of things, one about mass publics and one about political elites. About mass publics, what we can say is that the handful of people who do watch cable news are the most highly informed -- and therefore the most partisan and most highly ideological -- of all Americans (highly informed means they receive a lot of information, not that they necessarily get it right!). So the things they learn from watching cable news are not apt to change their minds about anything. At best, it gives them a vocabulary and some talking points with which to talk about issues of public policy.
About political elites...well, they do watch cable news, and are very tempted to design public relations strategies around "winning" news cycles there. This, as Obama has shown, is mostly a big waste of time. If they go farther and actually design policies around that goal, it's apt to be counterproductive. But, for those of us who are just observers, it's worth knowing that those impulses are real and sometimes drive action, foolish or not. In other words, ignore the yakkers, and you'll find some actions of politicians difficult to understand.
(Click through Ezra's link above to very sensible comments by Kevin Drum and Matt Yglesias on the same subject. I should also note that Kevin Drum is, I think, talking mainly about daytime cable news, but it's not as if prime time cable news is doing much, either).
Bottom line is that Ezra is right about this one, but it only took him seven words.